Automatic hot-box alarm



Oct. 21 1924.

J. W. CARMAN AUTOMATIC HOT BOX ALARM Fil y 29. 1923 Patented Oct. 21-, 1924.

UNITED STATES Jmns wmnmucmunn, or sm'r'rtit, wasrmmron.

AUTOMATIC HOT-BOX ALARM.

- Application flledlay 29, 1923. Serial No. 842,818.

To all whom it may concern:

Be it known that JAmzs W. GARMAN, a citizen of the United States, residing at Seattle, in the county of King and State of Washington, has invented certain new and useful Improvements in Automatic Hot-Box Alarms, of which the iollowing is a specification.

The invention relates to an improvement in automatic detectors of the presence of undue heat in any operating parts which are liable to heat.

The invention is particularly designed for use in connection with journal boxes, particularly of railroad trains, which as at present constructed and arranged require freuent inspection to determine their condition of heat.- The present invention is adapted particularly to energize the signal or sound an alarm in the event the journal box or other-operating parts to be protected reach a degree of heat, which while not necessarily dangerous is nevertheless an indication that corrections of conditions should be made; the invention also contemplating a further signal when the parts reach a higher and dangerous degree of heat to thereby advise first of the approach of the journal box or other operating parts toward the danger heat degree, and secondly, of the further heating of the parts to the dangerous degree. Thus in the event of a'journal box, the engineer or other authority will be advised by the first si al that the particular journal box from w ich the signal is given is starting to heat, and if this signal is disre arded will be advised by the second signa of the necessity for immediate attention to the part.

The invention will be hereinafter described more particularly in connection with journal boxes, though it will be perfectly apparent that one form of the invention at least is readily applicable as a heat detector and protector for any cooperating parts of machinery which are liable to heat through friction to a degree which will'interfere with the proper operation of the parts.

The invention is illustrated in the accompanying drawings, in which:

Fi 1 is a vertical sectional view illustratin t e application of the detector to a journa box, and showing a form more particularly adapted for the use of journal boxes on railroad trains and the like.

Fig. 2-is a view of aslightly modified form of the invention, in which the detector I is adapted for use in' connection with any tubular section 1 is closed by a removable cap 4, into which a pipe 5 o ens, the pi e 5 being in communication wit the train no system 1n any convenient manner. A piston 6 operatesun the tubular section 1 and has depending stems 7 which normally rest upon two independent and aligned fusible supports 8 and 9, the former of which melts at a less degree of heat than the latter. The tubular section 1 has near the upper end an outlet 10, which is terminally rovided with any suitable alarm (not shown or the like, said tubular section 1 being further provided below theoutlet 10 with a larger outlet 11 leading to the atmosphere.

In this form of the invention, assuming the element 8 to be fusible or melting at a rotective degree of heat, the heat of the ournal box 3 will first act to melt this element 8 permitting the piston 6 to move downwardly to the extent of the length of the element 8 and thus admit train pipe pressure to the outlet 10 to sound the alarm. The trainmen are thus notified that the particular journal is becoming unduly heated.

as a whistle If no attempt is made to correct this condition and the heat of the journal box increases, the element 9 will be fused or melted permitting the piston 4: to move to a int to uncover the outlet 11 and thus blee the train line system and set the brakes.

In Fig. 2 a modified form is shown, wherein. the signal control is electrical. In this form, the journal box or other cooperating part to be protected, indicated at- 12, carries a tubular section 13 removably 'threaded into a support 14, and said section 13 carries a casing 15. The casing 15 is formed with an interior insulated section. 16 and has a removable cap 17. A metallic plunger 18, or a'plunger of any material with a metallic annular band, is arranged within the casin 15 to bear on the insulated section 16. spring 19 bears between the cap 17 and the piston 18 and is of sufficient tension to move thepiston downwardly when the spring is free to act. The piston 18 isprovidedwith a depending stem 20, which stem normally rests upon fusible elements 21, 22, arranged in alignment and supported within the tubular section 13, the latter being formed with outlets 23 at appropriate points to permit the'escape of the melted portions of the elements. Thus the piston 18 is supported at a point in the casing 15 by the combined length of the piston stem 20 and the under lying aligned elements 21, 22. A contact element 24 is secured in the casing 15 and has a depending metallic extension 25 extending lengthwise the casing toward the lower end. A second contact point 26 is arranged diametrically opposite the contact point 24, and a third contact point 27 is arranged below the contact point 26 and diametrically opposite the extension 25 of the point 24. Circuiting conductors 28 lead from the points 24 and 26 and are connected to any desired form of signal, which signal may or may not include an annunciator to indicate the particular location of the operating detector. A conductor 29 is connected to the contact point 27 and leads to a distinctive signal, the conductor 28 of course being common to both signals.

in this form of the device under undue heat, the element 21. which fuses or melts at a lower temperature than the element 22, is melted and the circuit including the conductors 28 is closed by'the spring movement of the piston. Thus the initial signal and the annunciator dropped as the latter is operated. If this signal is disregarded and the heat continues to increase, the second element 22 is melted and the pistondepends to engage the contact 27, remaining however,

in engagement with the contact 24 through mediate attention is required to t e part on which the particular detector is arranged.

at I claim is:

1. A heat detector including a movable part, independent signalling conditions resultant from difierent positionsof such part, and independent fusible means to control the positions of such part.

2. A heat detector, comprising a movable member, control means operated in difierent positions of said member, and independent aligned fusible elements for supporting said member, said elements melting at different temperatures.

3. A journal box, a tubular section supported thereby, an upper outlet from the section leading to a signal, a lower outlet from the section leading to the atmosphere, a piston within the tubular extension to suecessively uncover said outlets, means to admit train line pressure for operating the piston, a fusible element arranged beneath the piston and adapted on melting to permit movement of the piston to uncover the upper outlet, and a second fusible element arranged between the first fusible element and the piston and adapted to be melted at a higher temperature than the first fusible element, the melting of both of said elements permitting movement of the piston to uncover the lower outlet.

In testimony whereof ll ailix my signature in the presence of two witnesses.

JAMES WILLIAM CARMAN. Witnesses:

Rosnn'r CATro, JOHN MQGILL.

ill 

